Tuning device for stringed instruments



Nov. 19, 1957 ROBINSON 2,813,448

TUNING DEVICE FOR STRINGED INSTRUMENT Filed Jan. 15, 1956 2 Sheets-Sheet1 INVENTOR. 8/6/4420 L. EOZ/NSO/V,

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Nov. 19, 1957 R. L. ROBINSON TUNING DEVICE FOR STRINGED INSTRUMENT 2Sheets-Sheet 2 Filed Jan. 13, 1956 i 4/ J42 //Z F/G. 5 %,62 z? 24 5INVENTOR.

M M :m w W 7 M My 0 W e L 0 M M m y 9 United States Patent O TUNINGDEVICE FOR STRINGED INSTRUMENTS Richard L. Robinson, Houston, Tex.Application January 13, 1956, Serial No. 559,067

3 Claims. (Cl. 84-297) The present invention relates to stringedinstruments, and in particular to a device for tuning the strings ofinstruments.

An object of the present invention is to provide a device for tuning thestrings of a stringed instrument, such as a steel guitar, and one whichis positive in action and enables the user to quickly and accuratelybring the tone of each of the strings up to the required pitch.

Another object of the present invention is to provide a tuning devicefor a stringed instrument which is sturdy in construction, one havingfew parts easily and quickly assembled, and one which is economicallypractical.

A further object of the present invention is to provide a device fortuning the strings of a stringed instrument which has means for tuningeach string individually and other means for tuning all of the stringsat once, enabling the user to bring the pitch of the instrument intoregistry with the pitch of another instrument.

These and other objects and advantages of the present invention will befully apparent from the following description when taken in connectionwith the annexed drawings, in which:

Figure 1 is a plan view of a portion of a steel guitar, with the tuningdevice of the present invention installed thereon,

Figure 2 is an elevational view of the assembly of Figure 1,

Figure 3 is a sectional view taken on the line 33 of Figure 2,

Figure 4 is a sectional view taken on the line 4-4 of Figure 2, and

Figure 5 is a sectional view taken on the line 55 of Figure 1.

Referring in greater detail to the drawings in which like numeralsindicate like parts throughout the several views, the tuning device ofthe present invention comprises a pair of plates and 11 arranged invertical spaced relation and connected together by a verticallydisposedend plate 12. The end plate 12 has a flange 13 projecting from its lowerend and extending into a recess 14 in one end of the sounding body 15 ofthe stringed instrument, the stringed instrument being here illustratedas a guitar of the type known as steel guitars, although the tuningdevice of the present invention may be adapted for use with otherstringed instruments if desired. Screws 16 and 17 fixedly secure the endplate 12 and the flange 13, respectively, to the body 15 of theinstrument, there being provided suitable holes in the end plate 12 forthe screws 16 and other countersunk holes in the flange 13 for thescrews 17.

The plates 10 and 11 are each provided with longitu-- dinally-extendingseries of holes, here shown as eight in number, through which extend alike number of vertically-disposed threaded elements, or bolts 18, eachhaving a portion inwardly of its upper end supported in the upper plate10 and a portion inwardly of its lower end supported in the lower plate11. The bolts 18 are 2,813,448 Patented Nov. 19, 1957 free to rotate inclockwise and counterclockwise directions and the head of each bolt 18is provided with a socket 19 to accommodate a wrench for efiecting therotation of the bolt 18.

A plurality of blocks 20, also eight in number, are arranged in side byside spaced relation between the plates 10 and 11 and longitudinallythereof. Each block 20 has a bore 21 extending from its upper face toits lower face and each block 20 receives in its bore 21 the end portionof one of the strings 22 to 29, inclusive,

of the instrument. A knot or bead, as indicated at 30,.

on the end of the string keeps the string from pulling upwardly out ofthe block 20. Each block 20 has a threaded bore 31 inwardly of one endand extending from the upper face to the lower face and is threadedlyconnected to the shank of one of the bolts 18 for vertical upward anddownward movement in response to rotational movement of the bolt 18 inclockwise and counterclockwise directions.

The strings 22 to 29, inclusive, are supported above the body 15 bymeans of a bridge 32 which is arranged longitudinally of the upper plate10 adjacent a longitudinally extending slot 33 which is cut in the upperplate 10 and through which passes the adjacent portions of the strings22 to 29, inclusive.

The bridge 32 has a horizontally-disposed threaded bore positionedinwardly of each end. A bolt 34 is threaded into the bore on one end ofthe bridge 32 and another bolt 35 is threaded into the bore on the otherend of the bridge 32. The bolts 34 and 35 are supported for freerotation inwardly of their heads 36 and 37, respectively, in posts 38and 39, respectively, which rise from each end of the upper plate 10.

The head of each of the bolts 36 and 37 has a socket 40 whichaccommodates a wrench for manually effecting the back and forth movementof the bridge 32 relative to the end of the body 15 to which is securedthe end plate 12 and the flange 13. The sockets 19 in the bolts 18 andthe sockets 40 in the heads of the bolts 36 and 37 are preferably of thesame size so that a single wrench may be used to efiect the verticalmovements of the blocks 20 to tune the strings separately or to effectthe back and forth movement of the bridge to adjust the pitch of all thestrings simultaneously. The heads of the bolts 18 constitutehand-actuable means for effecting the rotational movement of the bolts18 in clockwise and counterclockwise directions, and the heads of thebolts 36 and 37 constitute hand-actuable means for effecting the backand forth movement of the bridge 32.

The other end of each block 20 has a narrow portion 41 received betweenadjacent ones of a plurality of vertically-disposed guide pins 42 whichhave their ends anchored in holes provided in the plates 10 and 11 sothat the blocks 20 may move up and down without twisting or binding. Anut 43 is silver soldered to the lower end of each of the bolts 18 andprevents the upward movement of the bolts 18 relative to the plates 10and 11. A slot 44 extends longitudinally of the lower plate 11 andpermits the user of the tuning device of the present invention to insertthe strings of the instrument therethrough and into the respective oneof the bores 21 in the blocks 20. A cover 45 extends over the ends andopen front of the space between the plates 10 and 11 and encloses theblocks 20 in the shank portions of the bolts 18.

In use, the tuning device of the present invention may be attached toeither end of any stringed instrument. The strings of the instrumentwill be secured by one end to one end of the instrument and to theblocks 20 of the tuning device of the present invention. Rotation of thebolts 18 will tighten the strings and bring them to the required pitchwithout repeated trial and error tightv 3 ening and backingoflof thebolts 18. The bridge 32 ismovable to tighten all of thestringssimultaneouslyand therefore to adjust the-pitch of the instrument towhich the tuning device of'the present invention is atta'ch'ed'. Thetuning device of the present invention will keep th'e strings ofi'aguitar ii1-- tnnefor a longer period oftime than tuning devicespresently in use with little"- or no slipping of the strings.

What is claimed i's's" 1 A tuning device forastringed instrument"compris ing-a pairof plates arranged iin vertical spaced relation.

adapted to be positioned at 'orreend" of= the soundingbody of saidinstrument" and to be fixedly attached thereto;

a: block adapted to receivea-n end portion of' a*string" of saidinstrument positioned betweensaid platesand' connected to said i platesfor. vertical up-and down' move ment; and a-bridge arrangedlongitudinally ofthe upper one ofsaid plates and connected i to saidupper plate for counterclockwise directions; a blocle' adapted"toreceive an 1 endportion of astring of said instrument positionedbetween said plates and connectedto'said-threadedelement for: verticalupward and downward movement responsive to rotational movement of'saidthreaded element in clockwiseand countercleckwise-- directions; andabridge arranged longitudinally of the upper one of saidplatesandconnected to i said upper plate for back" and forth movement relativeto said one end of said body.

3. A tuning device for a stringed instrument comprising a pair of platesarranged in vertical spaced relation adapted to be positioned at one endof the sounding body of said instrument and to be fixedly securedthereto, a threaded element extending/through and supported in saidplates for rotational movement in clockwise and counterclockwisedirections; a'block adapted-to receive an end portion of a stringoftsaidinstrument'positioned between said plates and connected to saidthreaded element for vertical up-and down-movement responsive torotational movement of said-wthreaded element in clockwise andcounterclockwise directions, a bridge arranged longitudinally of theupper one of said plates and connected to said upper plate for back andforth movement relative to said one end of said body hand-actuable meansoperatively connected to-said threaded element for effecting therotational movements ofsaid threaded-elements in clockwise andcounterclockwise directions," and' other hand-actuable means operativelyconnected'to said bridge for effecting the A baclc and forth movement'of the latter.

FOREIGN-' PATENTS Lung etal Nov; 18, 1890: Fender Oct. 30, ,195-1-Germany Mar. 11, 1935

